Gas turbine engines include compressor, combustor, and turbine sections. Multiple flanged components within the gas turbine engine, in the spinning and static sections of the compressor and turbine, may be bolted together. On some flanges threaded bolt holes may be used. Stress concentrations may arise at the bolt threads, such as at or near the first engaged thread of the fastened joint.
U.S. Pat. No. 8,371,785 to Babej et al. discloses relates to a rivet nut with a base part and a cylindrical rivet section, the base part having a central threaded cylinder, an annular contact surface that is coaxial to the threaded cylinder in a plane perpendicular to the longitudinal axis of the threaded cylinder, and that has an axially aligned annular groove, said groove being arranged radially inside the annular contact surface and radially outside the cylindrical rivet section and said groove blending, on the radially inner side, into the outer surface of the cylindrical rivet section, and antirotation ribs being provided in the area of the annular groove. The invention is characterized in that the annular groove, when seen in an axial cross-sectional plane, has a U-shaped cross-section with a radially outer lateral wall which is relatively steep and which has, at the steepest point, an inclination to the center longitudinal axis of the rivet nut in the range of approximately 45 DEG to approximately −20 DEG, preferably of approximately 30 DEG to approximately 0 DEG. The volume of the annular groove is chosen in such a manner that across a range of sheet thicknesses adapted to the respective thread size there is room for the volume of the respective folded region of the rivet section inside the annular recess (80) that is formed by molding the sheet part into the annular groove of the element and that it does not project beyond the side of the molded sheet facing away from the annular contact surface.
The present disclosure is directed toward overcoming one or more of the problems discovered by the inventors or that is known in the art.